Dendritic fibrous nanosilica-enhanced adsorption enables efficiently catalytic removal of 2,4-dichlorophenol from soil

Soil contaminated by 2,4-dichlorophenol (2,4-DCP) is a substantial environmental concern because it poses severe health hazards. Fenton and Fenton-like oxidation in the removal of 2,4-DCP in soil has attracted considerable attention but suffers from low efficiency due to strong adsorption of pollutants by soil. In this study, the non-toxic catalyst (DFNS-Fe 2 O 3 ) was prepared by loading Fe 2 O 3 on dendritic fibrous nanosilica (DFNS) for degradation of 2,4-DCP in soil. DFNS-Fe 2 O 3 could rapidly remove 2,4-DCP within 120 min (98 %), and the removal rate maintained 70 % after 3 cycles of durability test. In addition, BPA, phenol and 2-CP could be efficiently degraded by DFNS-Fe 2 O 3 . •OH and •O 2 were the main reactive oxygen species (ROS) in the reaction. It is speculated that 2,4-DCP degrades through hydroxylation, substitution process according to the GC-MS results. The toxicity of 2,4-DCP and intermediate products were observed by Ecological Structure Activity Relationships Predictive Model program (ECOSAR). This work paves an avenue for rational design of heterogeneous catalyst on DFNS and their applications in chlorophenol contaminated soil.